Merge main into archy-hwconfig — reconcile probe/dedup/name work

Both sides independently fixed the serial-alias dedup and the ESP32
boot-reset races; kept the branch's defer-to-auto-detect for unpinned
preferred paths (single probe pass per cycle) on top of main's
advert-name threading, Reticulum name propagation and radio-first
routing. Modal keeps main's 'Set Recommended' naming + probe progress
bar alongside the branch's in-app firmware flasher step.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

core/archipelago/src/mesh/mod.rs

@@ -478,6 +478,31 @@ impl Default for MeshConfig {
     }
 }
 
+/// Whether a mesh config file has ever been written for this node — lets the
+/// boot path distinguish "operator explicitly disabled mesh" (file exists,
+/// enabled=false) from "never configured" (no file), which is the only case
+/// radio auto-enable should touch.
+pub fn config_file_exists(data_dir: &Path) -> bool {
+    data_dir.join(MESH_CONFIG_FILE).exists()
+}
+
+/// True when `new` differs from `old` in any field a running mesh session
+/// captured by value at spawn (device path/kind, advert name, region, PHY
+/// params, channel, manage_radio, TCP interface) — i.e. when applying `new`
+/// to a live service requires a listener restart. Fields the session reads
+/// live from shared state (broadcast flags, assistant settings, steganography
+/// mode, …) deliberately don't trigger a restart.
+fn session_config_changed(old: &MeshConfig, new: &MeshConfig) -> bool {
+    old.device_path != new.device_path
+        || old.device_kind != new.device_kind
+        || old.advert_name != new.advert_name
+        || old.lora_region != new.lora_region
+        || old.lora_radio_params != new.lora_radio_params
+        || old.channel_name != new.channel_name
+        || old.manage_radio != new.manage_radio
+        || old.reticulum_tcp != new.reticulum_tcp
+}
+
 pub async fn load_config(data_dir: &Path) -> Result<MeshConfig> {
     let path = data_dir.join(MESH_CONFIG_FILE);
     if !path.exists() {
@@ -773,7 +798,11 @@ impl MeshService {
             self.our_ed_pubkey_hex.clone(),
             self.our_x25519_secret,
             self.our_x25519_pubkey_hex.clone(),
-            self.server_name.clone(),
+            // The mesh-page "Name on the mesh" (config.advert_name) wins over
+            // the server name — it existed as write-only config with no reader
+            // until this line, which is why renaming on the Mesh page never
+            // changed anything on the air.
+            self.config.advert_name.clone().or_else(|| self.server_name.clone()),
             self.config.lora_region.clone(),
             self.config.lora_radio_params,
             self.config.channel_name.clone(),
@@ -1071,8 +1100,18 @@ impl MeshService {
     /// the actual probe on purpose — see `probe_device`'s doc comment.
     pub async fn ensure_probe_allowed(&self, path: &str) -> Result<()> {
         let status = self.state.status.read().await;
-        if status.device_connected && status.device_path.as_deref() == Some(path) {
-            anyhow::bail!("{path} is the active mesh radio — already connected");
+        if status.device_connected {
+            if let Some(active) = status.device_path.as_deref() {
+                // Compare canonical paths: /dev/mesh-radio is a symlink to the
+                // ttyUSB*/ttyACM* node, and a probe through the alias would
+                // still open the very tty the live session is holding.
+                let canon = |p: &str| {
+                    std::fs::canonicalize(p).unwrap_or_else(|_| std::path::PathBuf::from(p))
+                };
+                if canon(active) == canon(path) {
+                    anyhow::bail!("{path} is the active mesh radio — already connected");
+                }
+            }
         }
         Ok(())
     }
@@ -1121,7 +1160,32 @@ impl MeshService {
         let peer = peers
             .get(&contact_id)
             .ok_or_else(|| anyhow::anyhow!("Peer not found"))?;
-        let pubkey_hex = peer
+        // Cross-transport twin resolution: callers frequently hold the
+        // FEDERATION twin's contact_id (the UI's merged conversation row),
+        // whose pubkey_hex is the Archipelago ed25519 key — NOT a radio
+        // routing key. Sending a Reticulum resource with that prefix fails
+        // with "Unknown Reticulum prefix" (observed live 2026-07-28,
+        // image-over-LoRa to a merged contact). Route via the radio twin —
+        // same arch identity, radio-range id — whose pubkey_hex is the
+        // actual over-the-air routing key (RNS dest hash / firmware key).
+        let radio_peer = if peer.contact_id >= FEDERATION_CONTACT_ID_BASE {
+            peer.arch_pubkey_hex
+                .as_deref()
+                .and_then(|arch| {
+                    peers.values().find(|p| {
+                        p.contact_id < FEDERATION_CONTACT_ID_BASE
+                            && p.arch_pubkey_hex.as_deref() == Some(arch)
+                    })
+                })
+                .ok_or_else(|| {
+                    anyhow::anyhow!(
+                        "Peer is federation-only (no radio twin) — not reachable over the radio"
+                    )
+                })?
+        } else {
+            peer
+        };
+        let pubkey_hex = radio_peer
             .pubkey_hex
             .as_ref()
             .ok_or_else(|| anyhow::anyhow!("Peer has no public key"))?;
@@ -1259,12 +1323,44 @@ impl MeshService {
                 .map(|p| !p.reachable && p.arch_pubkey_hex.is_some())
                 .unwrap_or(false)
         };
+        // Transport policy: LoRa first when it can actually carry the message,
+        // then FIPS, then Tor. A federation-synthetic id (what the UI's merged
+        // conversation holds) used to ALWAYS take the federation path, even
+        // when the very same node was sitting one LoRa hop away — so chats
+        // between two radio-equipped nodes silently rode FIPS/Tor. If the
+        // federation contact has a REACHABLE radio twin (same archipelago
+        // identity, radio-range id) and the payload fits the radio, skip the
+        // federation branch: the fall-through LoRa path twin-resolves the
+        // routing key via peer_dest_prefix.
+        let device_connected = self.state.status.read().await.device_connected;
+        let radio_twin_reachable = is_federation_synthetic && !exceeds_lora && device_connected && {
+            let peers = self.state.peers.read().await;
+            peers
+                .get(&contact_id)
+                .and_then(|p| p.arch_pubkey_hex.clone())
+                .map(|arch| {
+                    peers.values().any(|p| {
+                        p.contact_id < FEDERATION_CONTACT_ID_BASE
+                            && p.reachable
+                            && p.arch_pubkey_hex.as_deref() == Some(arch.as_str())
+                    })
+                })
+                .unwrap_or(false)
+        };
         let mesh_only_mode = load_config(&self.data_dir)
             .await
             .ok()
             .and_then(|cfg| cfg.mesh_only_mode)
             .unwrap_or(false);
+        if radio_twin_reachable && !mesh_only_mode {
+            tracing::info!(
+                contact_id,
+                bytes = wire.len(),
+                "Radio-first routing: federation contact has a reachable radio twin — sending over LoRa"
+            );
+        }
         if !mesh_only_mode
+            && !radio_twin_reachable
             && (is_federation_synthetic || exceeds_lora || radio_federated_unreachable)
         {
             // Resolve the peer's pubkey/did. Prefer the live mesh peer table,
@@ -2088,6 +2184,7 @@ impl MeshService {
         save_config(&self.data_dir, &config).await?;
 
         let was_enabled = self.config.enabled;
+        let needs_session_restart = session_config_changed(&self.config, &config);
         self.config = config.clone();
 
         // Update the status to reflect new config
@@ -2112,11 +2209,31 @@ impl MeshService {
             status.firmware_version = None;
             status.self_node_id = None;
             status.peer_count = 0;
+        } else if config.enabled && was_enabled && needs_session_restart {
+            info!("Mesh session config changed — restarting listener to apply");
+            self.stop().await;
+            self.start()?;
         }
 
         Ok(())
     }
 
+    /// The service's current (last-applied) config.
+    pub fn config(&self) -> &MeshConfig {
+        &self.config
+    }
+
+    /// Restart the listener (if running) so it picks up out-of-band state a
+    /// spawn captured by value — currently the server name pushed by
+    /// `server.set-name`.
+    pub async fn restart_listener_if_running(&mut self) -> Result<()> {
+        if self.listener_handle.is_some() {
+            self.stop().await;
+            self.start()?;
+        }
+        Ok(())
+    }
+
     /// Get a reference to shared state (for RPC handlers).
     pub fn shared_state(&self) -> Arc<MeshState> {
         Arc::clone(&self.state)
@@ -2238,6 +2355,46 @@ async fn bitcoin_rpc_getblockheader_by_height(
 mod tests {
     use super::*;
 
+    #[test]
+    fn session_config_change_detection() {
+        let base = MeshConfig::default();
+
+        // Same config → no restart.
+        assert!(!session_config_changed(&base, &base.clone()));
+
+        // Every session-captured field individually triggers a restart.
+        let mut c = base.clone();
+        c.device_kind = Some(types::DeviceType::Reticulum);
+        assert!(session_config_changed(&base, &c));
+
+        let mut c = base.clone();
+        c.device_path = Some("/dev/ttyUSB0".into());
+        assert!(session_config_changed(&base, &c));
+
+        let mut c = base.clone();
+        c.advert_name = Some("RNode Shaza".into());
+        assert!(session_config_changed(&base, &c));
+
+        let mut c = base.clone();
+        c.manage_radio = !base.manage_radio;
+        assert!(session_config_changed(&base, &c));
+
+        let mut c = base.clone();
+        c.lora_region = Some("EU_868".into());
+        assert!(session_config_changed(&base, &c));
+
+        let mut c = base.clone();
+        c.channel_name = Some("private-net".into());
+        assert!(session_config_changed(&base, &c));
+
+        // Live-read fields must NOT force a session restart.
+        let mut c = base.clone();
+        c.broadcast_identity = !base.broadcast_identity;
+        c.announce_block_headers = !base.announce_block_headers;
+        c.assistant_enabled = !base.assistant_enabled;
+        assert!(!session_config_changed(&base, &c));
+    }
+
     fn mk_peer(contact_id: u32, name: &str, arch: Option<&str>, reachable: bool) -> MeshPeer {
         MeshPeer {
             contact_id,